INDIANAPOLIS (AP) — When Donald Brown was drafted by the Indianapolis Colts in 2009, the expectations soared.

The numbers did not.

Now, after three mostly disappointing seasons, Brown is getting a second chance to show the Colts what he can do for them — and he hasn't even let a midseason knee surgery get in the way.

"It's just a matter of staying positive, staying confident," Brown said Wednesday. "It (the injury) was frustrating, but you have to realize that 'I'm going to come back.' You know it could have been worse, it could have been season-ending, but it wasn't."

Instead, the often overlooked and overshadowed Brown returned from the torn cartilage faster and stronger than anyone anticipated. The injury occurred Oct. 7 on a last-minute 2-point conversion run that helped the Colts (4-3) complete a stunning rally to beat Green Bay 30-27.

At the time, few even noticed as a wild celebration ensued and the postgame chatter focused almost exclusively on what the win meant for their missing coach, Chuck Pagano, who had just been diagnosed with a form of leukemia. Brown had surgery a couple of days later and missed the next two games.

When he returned Sunday at Tennessee, Brown looked as if he hadn't missed a play. He ran 14 times for 80 yards and was Indy's overtime workhorse, running the ball on six consecutive plays before giving way to Vick Ballard and Ballard's incredible 4½-yard, twisting dive to win the game.

Those who know Brown best expected nothing less.

"I liked Donald coming out (of college)," said interim coach and offensive coordinator Bruce Arians, who was with Pittsburgh then. "I thought he was a hard downhill runner with great speed. He has shown flashes of that speed for us and I love speed. He is more than a professional, he's a top-notch pro. He's more than prepared every week. He prepares the young guys. He's a great leader in his room and he's an explosive player and you can't have enough of those."

It's just taken Brown longer than expected to become the Colts' primary runner.

Part of the problem was bad luck.

After selecting Brown and essentially naming him the future successor to Joseph Addai, Brown fought a constant battle to stay healthy. He was inactive for five games as a rookie, three more in Year 2 and became a regular on Indy's weekly injury report even when he played.

All along, Brown's demeanor never changed. He kept watching film, trying to improve and picking up tidbits that he figured would be beneficial when his next opportunity came along.

That happened last season when Brown carried 134 times for 645 yards, scored five touchdowns and averaged 4.8 yards per carry. It was the first time Brown played in all 16 games and the numbers were career bests, though his success was again overlooked in the midst of a dismal 2-14 season that gave Indy the No. 1 draft pick.

But when Pagano and his new staff arrived in Indy, they wanted Brown to understand he'd be a key cog in this rebuilding project. At one point, Arians and Brown sat down to talk strategy and agreed to use some of the running plays that had made Brown such a productive runner at UConn.

"His system is very similar to what we ran in college, very familiar," Brown said, referring to Arians. "We were on the same page."

Initially, Brown and the Colts struggled.

After turning Andrew Luck's first preseason pass, a short screen into a long touchdown, Brown rushed for only 155 yards on his first 43 regular-season carries. In Week 5, following a bye, Brown ran 17 times for 84 yards against Green Bay and produced similar numbers against Tennessee last weekend.

What changed?

"Some of those things we don't do as much anymore because it didn't fit what our offensive line could do," Arians explained. "He (Brown) has adapted to some of the things that they do well and as long as the line blocks well and the tight ends block well, he'll find a hole. He likes the power-gap stuff which he did a ton in college. We wanted to do that, we're still doing some of it, but not as much as we did in (training) camp."

The other pieces are falling into place, too.

Since Brown got hurt, Ballard, a rookie, has carried 40 for 164 yards. Carter, too, has hung onto the ball and is averaging 3.6 yards per carry, and his late 1-yard scoring plunge last weekend wound up sending the game into overtime.

Suddenly, the usually pass-first Colts are averaging 119.8 yards rushing, and it's made a big difference.

"It's awesome," Andrew Luck said. "When he (Arians) can keep calling runs and be confident in us, it's a lot of fun to be an offensive lineman."

Or, in this case, it's awesome to be Brown.

"Whatever the situation is," he said, "you just want to make the most of it."

NOTES: Arians ruled two starters, TE Coby Fleener and CB Vontae Davis, out of Sunday's game. Fleener injured his left shoulder and Davis hurt his left knee in the win at Tennessee. ... At Wednesday's practice LB Pat Angerer wore a boot to protect the right foot he injured during training camp and LB Jerrell Freeman wore a boot on his left foot. Both are starters.